Adding RJ48(?) female recepticle to AT&T T1 demarc--how to?

I'm an individual with a T1 installation in process of being installed. The Telco installed the T1 demarc. AT&T sent the Cisco 1841 router, 56k console, and cableling. BUT, the cable connecting the modem (or CSU portion of it) to the demarc appears to be a Ethernet cable with two RJ45 connectors. The demarc does not have a receptacle for it. See attached photo of demarc box. My research seems to indicate I need to add a RJ48x adapter.
How do I make the connection? If I need to added a RJ48x, then what is the wiring schematic.
Editorially: it would have been a simple matter for the Telco to have installed it, it seems.

Featured Post

If you run run a WordPress, you understand the potential headaches you may face when updating your plugins and themes. Do you choose to update on the fly and risk taking down your site; or do you set up a staging, keep it in sync with your live site and use that to test updates?

When it comes to security, there are always trade-offs between security and convenience/ease of administration. This article examines some of the main pros and cons of using key authentication vs password authentication for hosting an SFTP server.

This article is in regards to the Cisco QSFP-4SFP10G-CU1M cables, which are designed to uplink/downlink 40GB ports to 10GB SFP ports. I recently experienced this and found very little configuration documentation on how these are supposed to be confi…

Here's a very brief overview of the methods PRTG Network Monitor (https://www.paessler.com/prtg) offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail. The methods are covered in more detail in o…

Michael from AdRem Software outlines event notifications and Automatic Corrective Actions in network monitoring. Automatic Corrective Actions are scripts, which can automatically run upon discovery of a certain undesirable condition in your network.…